COMPARISON OF MODERN INTRAOCULAR LENS POWER CALCULATION FORMULAS IN THE ACCURACY OF EXTENDED DEPTH OF FOCUS (EDOF) LENS POWER ESTIMATION

To compare the accuracy of six modern intraocular lens (IOL) power calculation formulas in predicting refractive outcomes for extended depth of focus (EDOF) intraocular lenses.

A retrospective study conducted at the Department of Ophthalmology, National Taiwan University Hospital, Hsin-Chu Branch, Hsin-Chu City, Taiwan.

We retrospectively analyzed 30 eyes of 30 patients underwent phacoemulsification and implantation of Tecnis ZXR00 IOL (Johnson & Johnson Vision). Cooke K6, EVO 2.0, Hill-RBF, Hoffer^® QST, Kane, and Pearl DGSformulas were evaluated. Optical biometry was performed with Lenstar LS 900 (Haag-Streit AG, Switzerland). The refraction prediction error were compared at three months after cataract surgery. The mean absolute error (MAE), mean numeric error(MNE), and the percentage of eyes with prediction error(PE) within ±0.25 D, ±0.50 D, ±0.75 D, ±1.00 D, and ±2.00 D were analyzed.

Among the six formulas, the Kane formula demonstrated the lowest mean absolute error (0.64 ± 0.57 D) and mean numeric error (−0.60 ± 0.56 D), achieving the highest proportion of eyes within ±0.25 D of the target refraction (36.67%). The Hoffer® QST formula yielded the highest percentage of eyes within ±0.50 D (50.01%), whereas the Hill-RBF formula showed the poorest performance, with the largest errors and the lowest proportion within ±0.50 D (36.67%).

The Kane formula provided the most accurate and least biased refractive prediction for EDOF IOL implantation. The Hoffer® QST formula also performed favorably within ±0.50 D, whereas the Hill-RBF formula showed limited predictive accuracy. These findings suggest that formula selection remains crucial for optimizing refractive outcomes in EDOF IOL surgery.